Wong Ka Fai, Chen Wener, Ren Jianhan, Yang Yanqi, Lin Yifan
Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
J Clin Med. 2022 Dec 15;11(24):7428. doi: 10.3390/jcm11247428.
Objectives: Fixed appliance treatment with premolar extraction is often required after functional appliance treatment to relieve crowding and improve facial aesthetics in the Asian population. This study compared the treatment efficacy of two approaches for treating Class II division 1 malocclusion: functional appliance followed by fixed appliance treatment with extraction (two-phase) and fixed appliance treatment with extraction (one-phase). Methods: Growing skeletal Class II patients with an overjet of ≥6 mm treated with two- or one-phase orthodontics were included. The two groups consisted of 29 patients (mean age = 12.55) and 30 patients (mean age = 12.72), respectively. Pre- and post-treatment cephalograms were analysed and skeletal, dental, and soft tissue characteristics were compared using independent t-tests. Treatment changes were compared within and between groups using paired and independent t-tests, respectively. Stepwise discriminant analysis was performed to identify the variables that best predicted pre-treatment group allocations. Results: At baseline, there were no significant between-group differences in age, gender, cervical vertebral maturation, or overjet. The two-phase group had greater Class II skeletal discrepancies (ANB angle and Wits appraisal). During treatment, the two-phase group showed greater improvements in intermaxillary relationship and facial convexity compared with the one-phase group (p < 0.01). Following treatment, the two-phase group had a greater L1/APog distance (p < 0.05). Facial convexity and Wits appraisal were identified as parameters significantly influencing the clinicians’ decision to use a one- or two-phase approach. Conclusions: In patients requiring premolar extraction, two-phase (vs. one-phase) treatment produced greater improvements in the intermaxillary relationship and facial convexity.
在亚洲人群中，功能性矫治器治疗后常需拔除前磨牙进行固定矫治，以缓解牙列拥挤并改善面部美观。本研究比较了两种治疗安氏II类1分类错牙合的方法的治疗效果：功能性矫治器后拔除前磨牙的固定矫治（两期）和拔除前磨牙的固定矫治（一期）。方法：纳入采用两期或一期正畸治疗的生长发育期骨性II类患者，其覆盖≥6 mm。两组分别由29例患者（平均年龄 = 12.55岁）和30例患者（平均年龄 = 12.72岁）组成。分析治疗前后的头影测量片，并使用独立t检验比较骨骼、牙齿和软组织特征。分别使用配对t检验和独立t检验比较组内和组间的治疗变化。进行逐步判别分析以确定最能预测治疗前分组的变量。结果：基线时，两组在年龄、性别、颈椎成熟度或覆盖方面无显著差异。两期治疗组的II类骨骼差异更大（ANB角和Wits值）。治疗期间，与一期治疗组相比，两期治疗组的颌间关系和面部凸度改善更大（p < 0.01）。治疗后，两期治疗组的L1/APog距离更大（p < 0.05）。面部凸度和Wits值被确定为显著影响临床医生选择一期或两期治疗方法的参数。结论：在需要拔除前磨牙的患者中，两期（相对于一期）治疗在颌间关系和面部凸度方面有更大改善。
